I have the same model and after a number of logic boards and pretty much everything else during the warranty period, the overheating continues. It got really bad during the 10.6 install - system actually hit the hard temperature limit and shut down. Since the warranty was up, I decided to open the thing up and see what I could do as far as removing 4+ years of dust. There wasn't much in there. I then decided to replace the heatsink compound. What was there was a bit excessive - it oozed well beyond the chips. I cleaned both surfaces then applied new (although not high quality) paste with a bit more restraint than the repair depot folks did. It got a bit better, but any cpu-intensive task (for example, HD Netflix) would eventually bring the temperature to the 210F shutdown point. Further experimentation showed that basically anything that pegged the CPUs would result in both fans going to their max RPM (somewhere around 6000) but the temperature would eventually reach the shutdown point. I watched the CPU...
